Determine if 3H-veratridine and 125I-Condylactis toxin are probes for the sodium gate of eel electroplax and lobster nerve. If so, explore interaction with DDT and analogs and pyrethroids. Develop Villegas types from lobster axons and examine effect of DDT and pyrethroids upon 22Na-efflux from them. Determine molecular difference between wild and mutant (OP-resistant) house fly acetylcholinesterases. Examine effect of DDT on estrogen receptors in quail. Explore use of beta-bungarotoxin as presynaptic probe in Torpedo electroplax.